A system for genome-wide histone variant dynamics in ES cells reveals dynamic MacroH2A2 replacement at promoters

Our system recapitulates expected characteristics of the well characterized H3.3 histone variant, and show that we gain additional information by using a kinetic approach. Additionaly, our results on the less-studied MacroH2A2 variant revealed differential dynamic profiles of this “repressive” histone variant. Our results represent a novel approach to histone dynamics in mammalian cells, reveal unanticipated dynamic behavior of the MacroH2A2 variant in pluripotent cells, and provide a resource for future studies of tissuespecific histone dynamics in vivo. We use a pulse-chase strategy for carrying out genome-wide measurements of histone dynamics to several histone variants in murine embryonic stem cells and somatic tissues. Genomic binding profiles of histone dynamics in normal ES cells, along with their differentiated counter parts, in MEFs, determined by ChIP-seq.